COCCIDIOSIS IN BIRDS AND MAM^TALS 285 



oocyst mixture is spread on the split surface of a carrot it will 

 be quickly ingested. Dogs will take the inoculum readily if it is 

 injected with a hypodermic syringe into a frankfurter. The con- 

 centrated oocysts may be placed into a small capsule (No. 3 or 4) 

 and then administered to a cat, dog, or rabbit. In this way, a 

 measured quantity of oocysts can be given to the animal, but 

 this method lacks what may be an essential condition of the ex- 

 periment, namely, mixture with salivary secretions. 



Animals are inoculated with coccidia most easily by injecting the 

 inoculum directly into the stomach. A stomach tube for small ani- 

 mals such as rats, guinea-pigs, rabbits, chicks, kittens, and puppies 

 is readily contrived by cutting off the large open dilated end of 

 soft rubber catheters (Xo, 5 small to No. 15 large, according to 

 the size of the animal) and slipping it over the end of a Luer 

 syringe. Hard silk web catheters may be similarly used, and they 

 are undoubtedly easier to manipulate due to their greater rigidity. 

 This same advantageous feature, however, is frequently respon- 

 sible for perforation of the esophagus, so that the softer catheters 

 are preferred. With larger cats or dogs, an infant's size stomach 

 tube with funnel is more useful than the catheters. 



The passage of a stomach tube is greatly facilitated by stretch- 

 ing the head back as far as possible to reduce the pharyngeal 

 angle. This is particularly essential in the rodents as the proximal 

 position of their molars causes interference. It is well to lubricate 

 the tube by dipping the end of it into paraffin oil. The tube should 

 be held against the dorsal surface of the pharynx and firmly 

 pushed down the esophagus. It must be pushed by the cardiac 

 sphincter at which point a slight resistance will be felt, other- 

 wise back flow may develop and fluid will get through the glottis 

 and down the animal immediately. Once the tube is in position, a 

 measured quantity of fluid containing a known number of oocysts 

 may be administered. If the large stomach tube and funnel is 

 used, it is well to pour a small quantity of water through the tube 

 to wash through organisms which might be adherent to the 

 walls. 



It may or may not be necessary to anesthetize the animal before 

 passing the stomach tube. Dogs of any size, unless they are vicious, 

 will tolerate the operation without anesthesia. Cats should be 

 stupefied with ether before attempting intubation, though it is not 

 necessary with kittens. Rabbits as a rule do not require an anes- 



